Selective signaling system.



3. B. HARLOW. SELECTIVE SIGNALING SYSTEM.

APPLICATION .FILED MAY 6, 1915.

Patented Jan. 2; 191?.

in V6 flibh Mn BMW lam tract:

' section to can for mm; w His for railway :yste us to provide s gnaling means lilllWfsV system, whereby operator at it i1stent station may or :2 dcspetchc any cause indicate to him or the absence iar section r' diccti urusm 1S comi noel when no train is in e to gl cerol mdrcotm g, 5 riesignetes a section of single trecl; railway which. is insulated from acij zicciot and in the usual men- A pair or power leads 8 and, supplied with alternating CFIQIE' J extend parallel to the track hove connecteci with them transformer primaries 3.0, 2.1 and. 12, transformer primaries being located. at the opposite ends and the center each section. 1 with the o Coimcctco. 3 "site rails each end of the section track relays or magnets 13 and 1% which are normally c ergizecl over the rails from current supplied bv a transformer secondary 15 incluctive rclstion to the transformer primary 11..

ceszeiirvm'xrrs,

ac section is an answera motor 29 and a sing ...terru pters 21, 22 and pted to give :1 signal different 1e others.

The operation of the answer-back means is controlled by a selectively operated device 24. The selectively operated device 2% is connected with line w' and 26 and controlled from s despetcl'xefs 27 supplied with so impulse re y and a transmitter 29 therefor. iii'iclgcd across the line Wires and 25 at the dcspatchei station is a telephone recciver 36 ads ted to receive signals from the answer-back means at the track section. Switching means comprising electromagnetic 3i, 3&2, 53 and 3&- ere conditioned by the presence a train in the section, or by its absence therefrom, to include one or the other the interrupter-s :21, 22 and 23 in an unswccbuck circuit cxtenciing to the ties pitcher-s station after 'he operation of the sole rely operated device 2%.

in the operation of the system, the dapr-itcher desiring to secure a signal indicative of the condition of track section 5 will operate his transmitter 29 to cause the solestive device 24; to close contacts l0 and 4d,

ore of these contacts 40 and 4-1 oom- 'zing circuit for relays 42 1e iine wires 25 and 26 and close contacts and 45 sod new that there is a train 4-1 the section traveling in the direction indihy' the arrow. M ti is case, the track will. he denergized anal Wiliheve controlled thereby. The contact will open the cirthe y which may be traced from a common centimet e-r51 over conductor 2, through Winding of relay 33, over contor 53 3'16; through contact 50 to the opposite side of the inflection coil secondary 54-. The denergizstion 0E relay 33 closes contacts and 5-8 and opens contact 57. The closure of contact completes an energizing circuit for relay 32 from the transformer secondary 58, causing said relay tov pull up its (immatures and. close contacts mo 66 and open contacts (Wood 68. The closure of Contact 66 completes a circuit. which includes contacts 69 and 70 of the answer-hack interrupter 23 in an answerbecir circuitwhich may be traced from line.

r *1 one Wire 26 through condenser 71, contact 45,

armaturetiif motor 20, contacts 69 andll contact -56, conductors .72, contact as and;

26 which will be audible in the receiver 30,

and which will notify the despatcher that there is a train in block 5 moving in the direction of the arrow. This answer-back circuit will be conditioned for operation by the actuation of the selectively operated'means 24 so long as the train is in the section, although the energizing circuit for the relay 32 may be shifted irom the contact 55 of relay 33 to contact 76 of relay 81.. This is brought about by reason of the fact that as the train moves along the track section. 5 the potential of the track rails Within this section will shift,

' graduz lly strengthening toward the end from which the train entered and gradually weal:- ening toward the end Which-the train is approaching. As the train approaches, the transformer secondary 15 will shunt suil'cient current from the track magnet 14 to cause it to release and open contact 77. lhis will open the circuit of relay 31 causing it to release its armatures and close contacts 76 and 78. This will complete an energizing'circuit for the relay 32 from the transformer secondary 58 through the contact 76 which will be in substitute of the path over which it Was originally energized, which circuit may be traced from transformer secondary over conductors 52 and 51 through a normally closed contact of relay 34c, winding of relay 32, contacts 76 and 65, back to the transformer secondary, so that by the time the train has reached a position in the section 5 which will permit sufficient current to fiow through the track relay 18 to energize it and complete the energizing circuit for the relay 33, there will be no danger of the relay 32 becoming denergized.

Had the train been coming from the opposite direction to that shown and described, it would have brought the interrupter 21. with contacts 80 and 81 into the answer-back circuit through the deenergization of track magnet 14, and relay 31 and the energization of relay lit-this operation being precisely the same as that previously described for completing the answer-back circuit for interrupter 23.

Should it ha pen that there is no train in the track when the selectively operated device 24 set to close contacts 46 and 421, then both track magnets 13 and 142 will be energized, as will also relays 31 and 35, while the circuits of relays and 341 will be open, thus closing contacts and 82 and completing a circuit forincludmg the mai ens contacts of 83 and 841- of interrupter 22 in the answer-back circuit and the despatcher Wlll rece ve a tone in the receiver 30 in ac cordance with the code of interrupter 22,

and will know that section 5 is unoccupied.

l/Vhal' is claimed is:

1. In a. signaling system for single track railways, a railway track divided into sections, an answer-back mechanism individual to each section including a plurality of interrupters, selectively operated means for controlling the operation of said answerback mechanism, an answer-back circuit completed by the operation ofsaid selectively operated means, and switching means condi' tioned by the presence of a train in the section and its direction of movement to include in said answerback circuit one of two of the intcrrupters and by theabsence of a train from the section to include a third one of said intcrrupters in said answer-back circuit. i

2. In a signaling s stem for single track railways, a railway track divided into se ctions, an answer-back mechanism associated with each of said sections for producing a plurality of characteristic signals when operated, selectively operated means for controlling the operation of said answer-back mechamsm, an answer-back circuit completed by the operation of said selectively operated. means, and switching means controlled from said track to cause saidanswerback mechanism to send over said answerback circuit one or another of the signals depending upon the position and direction of movement-of a train with respect to a particular section.

3. In a signaling system for single trackrailways, a railway track divided intosections, an answer-back mechanism individual to each section including a plurality of interrupter-s, selectively opera-ted means for controlling the operation of said answerback mechanism, an answer-back circuit completed by the operation of said selectively operated means, a track relay located. at each end of each section, the track relay at one end of said section being operated by the entrance of a train in said section traveling in one direction and that at the other end of said section being operated by the entrance of a train in said section traveling in the opposite direction, and switching means separately controlled by the operation of be obtatincd.

el. In signaling system for single track railways, a railway track divided into sections, an answer-back mechanism individual to each of said sections and provided with interruptcrs, ach adapted to give a signal different from the others, selectively operated means for controlling the operation of said answer-back mechanism, an answerback circuit closed by-the operation of said selectively operated means, a normally en- Olg'iZcd track magnet at each end of each 01' said sections adapted to be deencrgized by the passage or a train through StlCl section,

switching means controlled by the track.

5. In a signaling system for single track railways, a single track railway divided into sections, an answer-back mechanism individual to each of said sections and provided uith three interrupters, each adapted to give a signal difi'erent from the others, selectively operated means for controlling the operation of said answer-back mechanism, an answerback circuit closed by the operation of said selectively operated means, switching means conditioned by the entrance into a section by a train from one direction to connect one ofsaid interrupter-s in said answer-back circuit, by the entrance of a train into said section from an opposite direction to con nect another of said interrupters in said answer-back circuit and by the absence of a train from said section to connect the third one of said interrupters in said answer-back circuit.

6. In a signaling system for single track railways, a railway track divided into sections, an answer-back mechanism associated with each of the sections for producing a plurality of characteristic signals when 0 erated, selectively operated means for controlling the operation of said answer-back mechanism, an answer -back circuit completed by the operation of said selectively operated means, and switching means controlled from said track to cause said answer-hack mechanism to send over said answer-back circuit one or the other of the signals, depending upon the direction of movement of a train in the particular section.

7. In a signaling system for single track railways, a railway track divided into sections, an answerback mechanism individual to each section and including a plurality of codifying devices, selectively operated means for controlling the operation of'the answerback mechanism, an answer-back circuit completed by the operation of the selectively operated means, and switching means controlled from the track and depending upon the direction of movement of a train in the particularsection' for operatively associating one of the codifying devices and the answer-back mechanism for sending over the answer-back circuit a characteristic signal.

In witness whereof, I hereunto subscribe, my name this 4th day of May, A. D. 1915.

JOHN BRAYTON HARLOW 

